Drafting instrument



y 15, 1969 E. L; BRANDYS 3,455,029

DRAFTING INSTRUMENT Filed April 2, 1968 2 Sheets-Sheet 1 Mug-55%;???

Inventor Edward L. Brondys By M M Attorney July 1 5, 1969 BRANDYs 3,455,029

DRAFTING INSTRUMENT Filed April 2. 1968 2 Sheets-Sheet 2 so 3 5 7a 79 Inventor 4" I l l z l Edward L.B rondys o oooooooooooooooooboooooooooogo'c o 000 B K 7 y A Q L6 Attorney United States Patent 3,455,029 DRAFTING INSTRUMENT Edward L. Brandys, 7750 Clarence Ave, Chicago, Il]. 60631 Filed Apr. 2, 1968, Ser. No. 718,075 Int. Cl. B431 13/24 US. Cl. 33-110 7 Claims ABSTRACT OF THE DISCLOSURE A drafting instrument for parallel line drawing of different spacings comprising a pair of elements having linearly slidable cooperative edges, at least one of the elements having a ruling edge angularly related to the slidable edges, a spaced pair of detents on one element for cooperation with a series of indents on the other element for incrementally indexing the elements as they slide along said slidable edges.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a plural-part drafting instrument and more specifically to a novel means for indexing at equal intervals a ruling part of the instrument with respect to a guide part thereof.

Description of prior art In prior art devices serrations are provided along c0- operating guide edges and the teeth of the ruling and guide parts intercollate. The ruling part is bodily separated from guide part to disengage the teeth and then the ruling part is moved toward the guide part and the teeth are reengaged in a displaced location. This constant shifting of the parts makes it difiicult to maintain register at equal intervals and requires the user to hunt for proper position. The task becomes tedious and any movement of the guide portion loses parallelism of the ruling edge with respect to the lines previously drawn.

SUMMARY OF THE INVENTION The present invention has for its primary object to provide a novel, simple to operate accurate instrument to facilitate drawing spaced parallel lines.

A further object of the invention is to provide a novel drafting instrument wherein each part provides linear guide edges in slidable engagement at all times with each other, the ruling part providing a ruling edge angularly related to said guide edges, and interlocking means being provided releasably interconnecting the two parts along said edges at regularly spaced increments, said interlocking means being releasable upon application of a force to the ruling part in a direction generally parallel to the guide edges whereby the guide edges remain in engagement during the displacement of the ruling part from each instant position to the next position.

A further object is to device a novel interlocking means between the aforesaid cooperating parts of the instrument wherein said means functions not only to gauge the incremental displacements between the parts along the engaging edges, but also functions to bias the ruling part in a direction engaging its guide edge with the guide edge of the guide part so that these edges cannot be separated or angled relative to each other but are caused to engage each other along their full opposing lengths whereby the ruling edge is maintained in parallelism with the lines previously drawn.

A further object is to devise an interlocking means between the aforesaid parts of the drafting instrument wherein one part comprises a series of regularly spaced notches, indentations or apertures along its ruling edge and the other part comprises a detent overlapping the notches etc. and adapted to enter each notch seriatim and thus index the ruling part.

An extension of the previous object is to provide a novel interlocking means comprising notches on one part and detents are spaced different distances than the notches so that the parts are adapted to interlock at increments less than the spacings between the notches.

Another object is to provide novel anti-slip supports to prevent accidental bodily displacement of the guide portion, said supports being resilient and holding the guide portion vertically spaced above the table or desk upon which it is used and accommodating displacement of the guide portion in situ toward the such desk or the like to increase the locking pressure of the detents carried on the guide portion against the underposed segment of the ruling portion.

These and other objects and advantages inherent in and encompassed by the invention will become more readily apparent from the specifications and the drawings, wherein:

FIGURE 1 is a plan view of one embodiment of the invention;

FIGURE 2 is an enlarged transverse sectional view taken substantially on line 2-2 of FIGURE 1;

FIGURE 3 is an enlarged transverse sectional view taken substantially on line 3--3 of FIGURE 1;

FIGURES 4A, 4B and 4C are transverse sectional views illustrating various detent arrangements;

FIGURE 5 is a fragmentary plan view of another embodiment of the invention;

FIGURE 6 is an enlarged transverse sectional view taken substantially on line 66 of FIGURE 5;

FIGURES 7 and 8 illustrate a further embodiment of the invention, FIGURE 7 being a plan view, and FIG- URE 8 being a transverse sectional view on an enlarged scale taken substantially on line 88 of FIGURE 7; and

FIGURE 9 illustrates a still further embodiment of the invention.

DESCRIPTION OF FIGURES 1-4C Describing the invention in detail and having particular reference to the drawings, there is shown a drafting device generally designated 2, comprising a rule portion 3 and a guide portion 4. In the present disclosure the guide portion is in the form of a protractor of trapezoidal shape having a base providing a straight guide edge 5 along which is adapted to slide a base guide edge 6 of the rule portion 3 which is in the form of a 30, 60, triangle having in addition to the base edge 6, a side edge 7 and the hypotenusal ruling edge 8, although it will be understood that any of the three edges 6-8 may be used as the ruling edge and the adjacent edge the guide edge.

The protractor in addition to the major base edge 5 comprises a minor base edge 10 and side edges 11 and 12 which may be used as ruling edges as hereinafter explained. A plurality of pads 14 of elastomer material are mounted in recess 15 (FIG. 5) and secured thereto by any suitable means as by a locking interlock or by any adhesive well known in the art.

As best seen in FIGURE 3, the pads 14 normally lift the guide element 4 a slight spacing 16 from the work surface 17 on a paper laid upon a worktable or support 18 until the user presses on the reverse face 19 of the guide element 4 compressing the pads so as to bring the obverse face 20 of the guide 4 toward or against the work surface 17. The function of these pads 14 is twofold, namely, to prevent the guide from sliding and further to augment the action of the locking element or 3 keeper 21 of the incremental divider or indexing assembly generally designated 22.

The divider assembly comprises a series of equally spaced apertures 24 inwardly along edge 6 on a line par-allel therewith, a series of equally spaced apertures 25 along edge 7 and a series 26 along edge 8. In lieu of the apertures as best seen in FIG. 4A, a series of depressions or notches 27, 28 may be provided in the reverse and obverse faces 29, 30 of the triangle along the respective edges 6-8 or the apertures may be countersunk a shallow or deeper counterbores 32 or 33 as seen in FIGS. 4B and 4C.

The apertures 24-26 or depressions 27, 28, generally designated indent means, are arranged to seat a detent or indexing ball 34 which is mounted in a vertical bore 35 at one end of a keeper 21. In the bore 35 there is provided a spring 37 compressed between the top of the ball and the upper closed end of the bore 35 urging the ball into engaged position with a selected one of the apertures or notches. The keeper overhangs at one end the respective edge portion of the ruling element and at its other end is secured suitably in any manner, herein shown as bolts 38, to the guide element 4. It will be noted that the ball or index guide bore 35 is slightly closed as at 39 at its lower end to prevent escape of the ball.

Now it will be noted, that the pressure at which the indexing ball 34 is held in the spacing apertures or notches will depend not only upon the deflection factor of the spring 37 but also upon the load imposed upon the guide element in compressing the pads 14. Thus the force of the interlocking hold is variable in accordance with the users desires and can be released to permit easy adjustment and pressed down to lock.

It will become apparent that the spacing between adjacent lines shown at 40 and 45 (FIG. 1) is the function of the sine of the angle. In other words, a A; inch displacement if such be the spacing between adjacent apertures will give you A; inch spacing between the lines 40 since the sine of 90 is unity. As the angle between the ruling surface and the guide edge becomes smaller, the spacing between adjacent lines will become smaller as is apparent from the lines shown at 45.

Referring now to FIGURES and 6, the parts corresponding to those of the previous embodiment are identified with corresponding reference numerals, that is the guide element 4 and the rule element 3 are guidably engaged along surfaces 5 and 6 and the apertures or indentations 27 are equally spaced for example on the order of A; inch. The feature of the present embodiment resides in providing in a keeper 49 a pair of indexing elements 50, 51 which have plungers 52, 53 which are spaced apart at their centerlines a distance equal to the distance be tween the notches plus one half the distance between adjacent notches. In the showing assuming that the distance between adjacent notches is then the spacing between the plungers is Thus upon relative moving of the members 3 and 4, each position will be 1 apart even though the notches 27 are 2 apart.'In this embodiment each plunger is vertically displaceable in its bore 55 and has a headed upper end 56 which seats at its lower end on the shoulder 57 and at its upper end provides a seat for the lower end of a compression spring 59 which is seated on the underside of a plug 60 secured or glued into the upper end of the enlarged bore portion 62. The keeper 49 is secured at its anchor portion 63 by rivets 64 or the like to the guide portion 4.

Referring now to the embodiment of FIGURES 7 and 8 wherein parts common to the other embodiments are identified by the same reference numerals in this embodiment, the guide element 3 is provided with a keeper 75 of spring metal which comprises an anchor portion 76 secured as by rivets 77, 77 to the guide element 3. A plural or furcated portion projects from the anchor portion 3 over the selected edge portion 6-8 of the rule element 4. The spaced legs 78, 78 are yieldable vertically and each has an upturned distal end portion 79 defining a node 80 with a rounded or sphered protrusion or indexing element 81 which is positioned to enter a selected aperture 2426 or depression 27, 28 in the rule portion attendant to the selected guide edge 6-8 engaging the edge 5. The protrusions 81 on legs 78, 78 are preferably spaced at any multiple of one and half the distance between adjacent apertures to subdivide the spacings between the apertures by one half. Of course a second series of apertures parallel to but linearly ofiset from the first can be provided and the legs or detents appropriately arranged so that various incremental spacings can be elfected.

FIGURE 9 shows a rule element 3a which in function corresponds to the element 3 and comprises the apertures 24, 25 which may be depressions if desired. The element 3a is an adjustable triangle having a base part and a movable part 101 which is mounted as by rivets 102 to one edge portion of a sector 103 which is pivotally connected as at 104 to the base part. The sector element 103 is provided with angular graduation along its arcuate edge 105 and is concentrically slotted at 106 to admit a locking assembly 107 which is secured to the base 100. The angular measurements are taken along the parting edge 108 of the base which in the closed position mates with the complementary edge 110 of adjustable part 101. As best seen in FIGURE 9 the distance between the adjacent lines is a trigonometric function of the angle, it being readily apparent that the spacing between adjacent lines 111 at an angle of 70 is greater than at an angle of 20.

Several embodiments of preferred form have been shown to illustrate the principles of the instant invention. However, various other forms will now become apparent to those skilled in the art without deviating from the spirit of the invention the scope of which is set forth in the appended claims.

I claim:

1. A drafting instrument comprising a guide element and a rule element having engaging linear guiding edges accommodating slidable movement of the rule element lengthwise along said edges, said rule element having a ruling edge angularly related to said guiding edges, a series of uniformly spaced indent means on one of said elements spaced inwardly from its said guiding edge, detent means on the other of said elements and having a portion projecting over the said guiding edge on said one element and overlapping said indent means on the one element and yieldably biased into cooperative asso ciation with a selective one of said indent means on the one element and engaging the indent means on the one element seriatim attendant to relative movement of said elements lengthwise along said guiding edges whereby positioning the ruling edge at regularly spaced increments, said detent means on the other element comprising a keeper means on the other element and springurged balls mounted in the keeper means and movable transversely of said elements, and the balls being spaced on the order of one of the balls engagingly cooperating with a selected indent means on the one element while the other of said balls being disposed medially between a pair of adjacent other indent means on one element and said balls alternately engaging succeeding indent means on the one element as the one element is incrementally displaced linearly along said guide edges.

2. A drafting instrument comprising a guide element and a rule element having engaging linear guiding edges accommodating slidable movement of the rule element lengthwise along said edges, said rule element having a ruling edge angularly related to said guiding edges, a series of uniformly spaced indent means on one of said elements spaced inwardly from its said guiding edge detent means on the other of said elements and having a portion projecting over the said guiding edge on said one element and overlapping said indent means on the one element and yieldably biased into cooperative association with a selective one of said indent means on the one element and engaging the indent means on the one element seriatim attendant to relative movement of said elements lengthwise along said guiding edges whereby positioning the ruling edge at regularly spaced increments and yieldable displacement inhibiting means mounted on said guide and defiectible transversely of said elements and adapted to support the guide in slightly elevated relation to an associated work support and the rule element, and said guide being defiectible by the user toward the support to vary the biasing of the detent means thereon in relation to the indent means on the rule element to selectively facilitate and inhibit relative movement therebetween linearly of said guide edges.

3. The invention according to claim 2 and said indent means on the one element comprising a series of notches formed therein.

4. The invention according to claim 2 and said indent means on the one element comprising a series of transverse apertures therein.

5. The invention according to claim 2 and said rule element being a geometrically shaped structure presenting a plurality of ruling edges angularly related to said guide edge of the guide element and said uniformly spaced indent means being disposed lengthwise inwardly along each of said edges.

6. The invention according to claim 2 and said rule element comprising an adjustable triangle having a portion pivotal on an axis transversely of the elements and positionable at a plurality of angles with respect to the guide edges.

7. A drafting instrument comprising a guide element and a rule element having engaging linear guiding edges accommodating slidable movement of the rule element lengthwise along said edges, said rule element having a ruling edge angularly related to said guiding edges, 21 series of uniformly spaced indent means on one of said elements spaced inwardly from its said guiding edge, detent means on the other of said elements and'having a portion projecting over the said guiding edge on said one element and overlapping said indent means on the one element and yieldably biased into cooperative association with a selective one of said indent means on the one element and engaging the indent means on the one elemet seriatim attendant to relative movement of said elements lengthwise along said guiding edges whereby positioning the ruling edge at regularly spaced increments and said detent means on one of the elements comprising a bifurcated spring metal member having a pair of legs overlapping the other element and biased toward the same, each leg having a projection thereon directed toward the other element, and the projections being spaced 0n the order of one of the projections engagingly cooperating with a selected indent means on the one element while the other of said projections being disposed medially between a pair of adjacent other indent means on one element and said projections alternately engaging succeeding indent means on the one element as the one element is incrementally displaced linearly along said guide edges.

References Cited UNITED STATES PATENTS 345,989 7/1886 Podgorski 331 10 1,208,266 12/1916 Beaumont 33-81 1,712,106 5/1929 Elam 33110 2,080,792 5/1937 Simmons 331 10 2,841,876 7/1958 Pittenger 3317O 3,111,765 11/1963 Rodgers 33110 X FOREIGN PATENTS 59,774 6/ 1913 Austria. 638,448 4/ 1962 Italy. 442,973 7/ 1912 France.

OTHER REFERENCES Product Engineering, Indexing Devices Sept. 1, 1958, p. 49.

HARRY N. HAROIAN, Primary Examiner 

